Adjusting mechanism for slit lamp apparatus



`Fume 14, 1960 Filed March 7, 1955 o. G. oswoLD 2,940,357

ADJusTING MECHANISM FOR sLIT LAMP APPARATUS 2 Sheets--Sheei 1 Fla! `une 14, 1960 o. G. oswoLD ADJUSTING MECHANISM FOR SLIT LAMP APPARATUS 2 Sheets-Sheet 2 Filed March 7, 1955 l1. I l I l l l l INVENTOR.

OLUF G. OSWO L D ATTORNEYS nitecl States Patent ADJUSTING MECHANISM FOR SLIT LAMP APPARATUS Oluf G. Oswald, Richmond, N.Y., assignmto Bausch &

Lomb Optical Company, Rochester, N.Y., a corporation of New York Filed Mar. 7, 1955, Ser. No. 492,631

3 Claims. (Cl. 88-20) This invention relates to ophthalmic instruments and more particularly it has reference to an adjusting mechanism for a slit lamp apparatus.

Ordinarily, a slit lamp apparatus is classified as either one of two principal types. The rst type has the light source mounted to swing about an axis far removed from the patient being examined but close to the diagnostician. The second type has the light source and microscope mounted to move about a single common vertical axis of rotation which may be positioned so that it passes through the eye of the patient under examination. The current trend has been toward the second type of instrument wherein during an examination the axis must be shifted from one eye of the patient to the other. Once the light source and microscope have been so shifted, it is necessary to make an accurate adjustment of the instrumentto align the light source and microscope with the exact area of the eye in question. One such instrument currently on the market has a universally mounted actuating means for positioning a light source and microscope relative to the eye of a patient and has the operating mechanism exposed so that it can become caked and fouled with dust and moisture which can impair its operation. This particular instrument also has some of its parts held together by gravity in such a manner that a slight bump can upset or dislocate parts of the instrument. t

Other current instruments have equally unsatisfactory means for supporting and moving the light source and microscope relative to the eye of the patient. y

lt is, therefore, a primary object of this invention tol overcome the above-noted disadvantages of the prior artv and to provide a'slit lamp apparatus having an improved adjusting mechanism which will be sensitive and accurate in operation, yet relatively simple and ruggedin Vconstruction. .Y

It is another object of this invention to provide a slit', lamp apparatus having an improved adjusting means ca,

pable of precise and smooth, continuously variable adjustmentsof the light source and microscope relatlve to the area of the eye in question.

' It is still another object of this invention to provide slit lamp apparatus having animprovedadjusting mecha. nism that is enclosed in such a way as to cover and pro-4 tect the operating parts from dust and damage.

It is a further object of this invention to provide a slit, lamp apparatus having an improved adjusting mechanismthat is adapted to be easily manufactured and rapidly assembled.

And a still further object of this invention is to provide a slit lamp apparatus having an improved adjusting mechanism that is compact in size yet is capable of pro-v l. tol turn either together or relative to each other.

ice I bodying the present invention, certain parts being broken away to better show details of construction.

Fig. 2 is an exploded view showing the slide mountings for the carriage of the device.

Fig. 3 is a view showing two positions of the lever for effecting movement of the carriage.

Fig. 4 is a perspective view, partly broken away, showing the means for eifecting movement of the carriage. F Fig. 5 is a sectional view taken on the line'S-S of Referring to the accompanying drawings, and more particularly to Fig. 1, there is shown a slit lamp apparatus comprising a base 10 having a at, horizontally positioned top surface 10'. Attached to one end portion of base 10 is a bracket 11' which supports a head rest 11 having a chin rest 12 which is vertically adjustable by means of a nut 13 engaging with the threaded portion 14 whereby the head of a patient supported on the chin rest 12 can be comfortably positioned for examination.

Lying substantially parallel to, spaced from, and movably carried by the top surface 1G' of the base 10 is a carriage 15 which has supported adjacent one edge of its top portion 15 a pivot member 16 having an upwardly extending vertical axis of swing 17 about which a light source 18 and an observation microscope 19 are mounted wardly extending from the top portion 15' of the carriage 15 is a hollow lug 2t) which has seated against the upper end thereof a nut 21 into which is threaded a stud 22 rigidly fastened in depending relation from the under portion of an arm 24of the motion transmitting element 25 operatively connected to the pivot member 16 in such a way that turning nutv 21 will slide the motion transmitting element 25 vertically for raising and lowering the light source 18 and microscope 19 relative to the base 10 for aligning said instruments with the eye of a patient. A ball 26 and detent type stop means 27 are provided between the microscope 19 and the light source 18 for locking said instruments in fixed position relative to veach other. A narrow band of illumination may be projected from the light source 18 into one eye of a patient whose head is supported on the head rest so that the observation microscope 19 can be used to view the illuminated portion of the eye.

A means for mounting said carriage 15 for longitudinal and transverse movement relativeto said base 10`comprises a pair of spaced tracks 29, 3G positioned longitudinally of and fastened on said base 10 in cooperating relation with a mating pair of spaced tracks 31, 32 carried oy a plate 33.` Mounted on said plate 33 at right' angles to said tracks 31, 32 is a pair of transversely positioned tracks 34, 35 which are adapted to cooperate with a mating pair of tracks 37, 38 formed in the block 39 which is carried by the underside of the carriage 15. Ball bearings 40 are freely rotatable in ball bearing cages 41 which are positioned between each set of mating tracks so that said plate 33 may move longitudinally relative to the base 16 and said carriage 15 may move transversely relative to said plate 33 whereby said carriage 15, light source 18 and microscope 19 will be freely movable longitudi.` Mountednally and transversely relative to vthe base 10. at the end of each track 29, 30, 31, 32, 34, 35, 37 and 38 is a stop element 4l', only a few such elements being shown in Fig. 2. Each element 41' is constructed and arranged to prevent excessive horizontal and transverse movement of the carriage in any one direction.

apparent that they are held against movement in a vertical direction.

Depending from the edge of said carriage 15 is a skirt portion 42 which'is adapted to conceal the operating` parts' Y.of the above-enumerated means for mounting the carriage for movement. The top portion 15' of the s'ize of the skirt portion onthe carriage and the relative sizes of the carriage and base combine to produce a structure that is both dust-free andistable-in .that foreign matter .cannot get onthe operating parts nor can the carriage overlap the edge .of the base in-an unstable manner.V This results in amore stable, heater, andfm'oreefliciently operating mechanism.

Longitudinal and transverse movement .of the carriage 15 relative to` the base lis'Y effected lby a lever 43 having a narrow portion 44. whichextends through an over- Y sized opening 46 in the top .portion 15' of `the carriage.

15.adjacent .the edge thereof-and-oppositethefedge-carrying the pivot member .16. Mounted on fthe ,top fsurface 1i'..of the base is a flat frictionsurface -47 /whichfis @adapted to be contacted by a convexfsurface 'of revolution 48,V Ysuch as a spherical surface, formedY on a member 49 sup- Y ported bythe lower end of said lever 43. .The areaof said surface-47 Vis of such-extent that the opening 46 will Yr always overlieY a portion ofthe surface 47 for all positions of the carriage 15. Said friction surface 47 caribe Y formed of Iany material that is adapted to create a'resistance Ato sliding without being abrasive and can be of the type sold under'the trademark .Nylon and commercially designated as ENI-10001. Slidably mounted on said narrowportion 44 of the lever43 between thecarriage 15 ,andVv the member y49 isan rzulertured ,-.ball V50 which :is

adapted tov fit into a'seat 52 von the Vcollar ,53 threaded into, the .oversized Y'opening 46.7Y Carried by the Vlever 43 -betweenvthe'ball 50 and the member-49 is Ya spring 55 forurging said ball 50 and said convex surface of revolutionV YiS- of .the member 49 into-engaging relation, respectively,jwith2the seat 52 Vand with said frietionrsurface 47..

on the'top surfaceof theY base 10. The ball S0 may be of a diameter slightly larger than the diameter of lthe 4 A force on the lever 43 will cause the convex surface of revolution 48 -to roll on vthe friction surface 47 whereby the ball S0 will slide in the seat'52 for moving the carriage 15 a small distance relative to the base.V

When a force is applied to the upper portion of the lever 43 in a longitudinal direction, the carriage 15 will be constrained .to move in `the longitudinaldircction relative to thetbase'f'by -means'oflthetraks 31,132'and 29, 30. Likewise, when aY force is`applied'to the lever43 in a transverse direction, the carriage -15fwill `be.-.eonstraine'd to 'omove in .the transverse .direction lrelative to the -base by means of the tracks 34, .35 and.37,.38. Y.Howeven when a force isapplied lto thefle'ver in a diagonal direction, the carriage 15 fwill "be constrained to move in the` diagonal direction lelativeto thefbas'eaiong a line which will be .theV resultant of the longitudinal and transverse components of the movement. .Y

Any Amovement'ofthe upper end-of theglreverf43 will bereduced :to a vsmall proportion thereof Vwhen transmitted to the carriage 15, so that veryjdelicate adjustments of the light source.. and microscopercan be made relativeto Ythe eye Vof the pa-tient Vbeing examined.

'Itwill .be .seen that thereis here provided an .imj Y Although only one-embodiment of this invention has been shown and described in detail, it will be understood that other embodimentsV are possible and 'changes' may be opening whereby the Vball may be seated against the edge of the oversized opening 46 without departing from` 'Y the. spirit of or affecting the .scope of my invention..

Y vSaid spring urges the convex Vsurface of revolution 43 .of the member 49 into engaging relation with the at 'friction-surface 47. The strength ofsaidspring. 55 issuch Y, that the frictional engagement between the convex AsurfaceA and the friction surface-47 maybe overcome 'by Yexerting suflicient force on Ythe carriage 15 :in any .directionrwith the contines ofthe -top surface of the base-10 for producing grossmovementof the carriage. The microscope l9fand light source V18V Acan be shiftedfrom align-i ment'with VoneV eye of the patient to alignment with .the

l other; eye ofthe patient by overcoming the frictional resistance .between the convex surface 48Yandfriction surface 47 vwhereby the Yconvex surface 48of member v49'isV slid over .thefriction surface 47 for positioning the Yvertical axis Y 17 of .the pivot 16 in approximate alignmentrwiththe other eye of the patient.. Thefrictional'resistance .between'fthe convex surface 48 and the friction surface 47 `mustbeV such that'it can be overcomereadilyfor gross movements ofthercarriage 15 andl stillY beV strong enough to hold'the Y carriage 15 infxed position when the light vsource' 18 Vand microscope Y179 are swung about the pivot member16;

In'othe'r words, the frictional resistance must be such that once the carriage is adjusted relative to the eye of the patient, the light source v18 and microscope 19 are held in position without the need `of Yadditional holding -meansff a V'The ne adjustment of said .vertical Aaxis 17 withY Yrespect V:to Vthe precise portionfo'f the eye of the .patient .Y Yunder examination is accomplishedby grasping theflever Y 43 :and exerting a force .in the direction in whiehit is desired Vto move the .light source .18 and .microscope 19.

made inV the. form and 'arrangement of the parts and sub. stitutions may :bejmade zthereimwi-thout departing from the .spirit of the invention. as deliued in 'the appended claims. Y .Y

` bination comprising mountingzmeans connectedbetween the base and the carriageforsupporting the `carriageon Y he baselfreelyrmovable relative.theretoin a-jhorizontal plane, .and an actuator Vindependent of said ,mounting means for foontrollably moving .the carriage .relativertothe baise, said-actuator including ah'andle portion .extending throughthercarriage and mounted thereon for-limited universalmovement, and alfriction drive'portion iixed to said handle portion at the lower end thereof, .said fric-A tion drive portionhaving aY convex .smoothly curved sui-.-

face in frictional engagement with thetop A'surfaceoftheY base, and si'njin'gmeansV operatively dipo'sed between .thelv carriage andasaid fxicti'on'rdrive.portion forY keeping said curved surface inV relatively uniformV pressure Vengagementagainst the top surface'o'f the base.

2. Ina slit lamp .apparatus of the type including 'a base having arat horizontal top surface, anda carriage Ymovable-in a horizontal plane abovesaid surface, the cornbination comprising mountingV means connectedfbetween the base and the carriage for supporting the carriage on Vthrough'the carriage and having a friction drivepo'rtion fixedy .at itslower end, said .friction .drive portion Vhaving a convex smoothly curved surface in a Vvfrictional engagement Vwith the top 'surface ofthefbalse, .a socket 'xed in thecar'riajge varound said handle, ball loosely mounted on said handle, and a compression spring disposed between said ball and said drive portion for urging said curved surface into relatively uniform pressure engagement against the top surface of the base.

3. In a slit lamp apparatus of the type including a base having a :dat horizontal top surface, and a carriage movable in a horizontal plane above said surface, the combination comprising mounting means connected between the base and the carriage for supporting the carriage on the base freely movable relative thereto in a horizontal plane, and an actuator independent orr said mounting means for controllably moving the carriage rel ative to the base, said actuator including a handle portion extending through the carriage and having a friction drive portion xed at its lower end, said friction drive portion having a convex spherically curved surface in irictional engagement with the top surface of the base, a socket xed in the carriage around said handle, a ball loosely mounted on said handler, and a compression spring disposed between said ball and said drive portion for urging said curved surface into relatively uniform pressure engagement against the top surface of the base.

References Cited in the tile of this patent UNITED STATES PATENTS OTHER REFERENCES Berliner Text: Biomcrosoopy of the Eye, vol. 1; published by Paul B. Hoeber, Inc., Medical Book Dept. of

Harper & Brothers. Page 57. Copy of said volume in Bausch & Lomb Scientic Library (Group U; Acc. No.

20 747; dated November 6, 1943). 

